LIFE-CYCLE OF " CYSTOBFA " IRREGULARIS (mINCH.). 39 



same Gi'egarine. Different degrees in the process of incor- 

 poration are exhibited by different nuclei. I have arranged 

 them in a series. Eacli of the daughter-nuclei seen at a 

 possesses one little karyosome, corresponding, in all proba- 

 bility, with one of the spherules of the original karyosome, 

 which became divided up in the parent-nucleus as seen in 

 fig. 45. With successive divisions of the nucleus, these 

 daughter-karyosomes have been passed on and, as it were, 

 apportioned out among the daughter-nuclei, till by this time 

 many of the latter have only one, or the fragments resulting 

 from one. The periphery of each stains deeply, and the 

 interior part also stains rather more than hitherto (compare, 

 for example, fig. 45), as if the chromatin were becoming pre- 

 cipitated or re-converted into the customary staining-form. 



Nuclear incorporation of the fragments. — These 

 little karyosomes next divide up and gradually become in- 

 distinguishable from ordinary chromatic grains. In fig. 48 b 

 the first stage in tliis division is shown; each of the daughter 

 karyosomes has divided into two of about half the size. 

 Further division takes place more or less irregularly, as in c, 

 followed by d and then e. Sometimes the fragments may 

 remain together after division and form a ring or chain of 

 grains or rodlets, as in/ and g (compare again the nucleus 

 of Gr. blattarum). As the process goes on the grains tend to 

 stain up more homogeneously with the chromatic stain. From 

 either e or g — in both of which the nucleoplasm, as a whole, 

 is becoming chromatically denser — it is but a slight step, on 

 the one hand, to fig. 47, or on the other to fig. 46. In the 

 former are drawn two nuclei from different multinuclear 

 sporonts in about the same phase, a being taken from one 

 still in the vessel and h from one that was evaginated.^ Some 

 of the chromatic grains, particularly in a, are large and 

 prominent. 



* It will be noticed that, although both a and b are nuclei of the fourth 

 generation, a is distinctly the larger ; there is, of course, a certain variation in 

 the size of different sporulating individuals, which is manifest also in their 

 nuclei, karyosomes, etc. 



